Process of extracting radium compounds.



H No Drawing.

staining. materials, generally pitch blende or- UNITED ST PATENT FICE' FERDINAND .ULZER AND..RUDOLF SOMMER OF AUSTRIA-HUNGARY.

raocnss or EXTRACTING RADIUM COMPOUNDS.

' To all whom it may concern:

@Technical High School of Vienna, and RU- 5 DOLF SOMMER, chemist, subjects of the Emperor of Austria-Hungary, residing in Vienna, Austria-Hungary, and whose post- .oflice address is 5.9 VVahringerstrasse, Vi enna, Austria-Hungary, have. invented a dium Compounds from Radium-Contain- I ing-Substances'; 'and we do hereby declare .the following tobe a full, clear, and exact description of the invention, such as will appertains to make anduse the same.

The process hitherto known and exclusively used in practice for manufacturing radium,- first described by Curieand Debirne, consists in boiling the radium-conresidue from its treatment with. concentrated soda lye, filtering, treating the residue with ordinary hydrochloric acid, filtering again, washing with water, then boiling in an excess of concentrated soda solution,

. filtering, carefully 'washing with water and decomposingby means of pure hydrochloric acid. 'lheseoperations have to'be repeated at least three times, in order to get the greater portion ofthe radium into solution. The raw 'chlorids obtained mustthen be purified in yarious manners before thev are process is exceedingly tedious and expensive, owing to the fact that it is necessary to treat the whole of the other chemical compounds accompanying radium, namely .5 10,000 kg. per gram of radium, up to the moment of the last extraction by means of hydrochloric acid. It istherefore necessaryto use an excessively large quantity of chemicals, but chiefly the washing operations are so complicated and difficult that the process in question alone occupies several months (see Haitinger'& Ulrich,'lieports of the Imperial Academy 0 "Sciences, =V'01LCXVII, sect-ion 11 May, 1908, pages 142). It will be obvious that the exces sively high price and the great difficulty of obtaining radium. preparations are due. to theaboveprocess, K

The present: invention consistsin the dis-2 covery -of the fact that the so-called raw sulfates obtained from the hydrochloric acid solution of radiumchlorid by pr'ecipi I Specification of Letters Patent.

new and useful Process ofExtractingRaenable others skilled in the art to which it ready for fractional crystallization. U The.

three times, and the solid bodies" Patented Aug. 22, 1911.

Application filed'Septemb'er 1, 1909; Serial No. 515,637.

' tation with sulfuric acid, can be obtained m a much shorter time, even in a few days,-

and at'a. considerably smaller cost, by treat:

'ing the radium-containing substances by a process comprising only the alternative combination of a treatment with sulfuric acid or agents developing sulfuric acid' (such as bisulfates) with a treatment at; kaline agents in such a manner th, jected after thorough washing and fil to the following treatment, wherebyi of the alkaline treatment being the s ends a final treatment with sulfuric acid isfemployed.

'. The process may be carried out in the following manner: The radium-containing substances are boiled for several hours with concentrated sulfurlc acid, or exposed to the action of concentrated sulfuric acid at normal temperature for some weeks or melted with bisulfates. The residue, remaining after repeated washing with water and filtering, is boiled with causticalkalis or carbonates of alkalis at a high pressure or melted therewith and the resi due remaining after repeatedwashing with water and filtering is boiled"with 1diilute sulfuric acid. It may be stated that the order of the stages of the process may be varied, so that the same final effect is obtained by v treating first with alkaline agents and then with the acid agents. this process, about half of the admixtures are removed by "the treatment with acid agents, and the greater portion of the other compounds is removed by the treatment with alkaline substances, so that there re-3.,

mains only a residue ofabout half per cent. in which almost the whole radium iscontained in the form'of sulfate. As thewashing process is mostly completed and with little difliculty. The ravt sulfates may be converted quickly and almost completely into'the raw, chlorids, byfnielting -them'with alkaline carbonates or' mixtures of said carbonates, washing-thoroughl'yiwith water, filtering, and dissolving theresidue in pure hydrochloric acid. 'The following examples will 'give a better idea of the proc-' ess. Pitch blende contains silicic acid, ox

ids of iron, aluminum,zinc, lead, calcium, strontiuni,'bari1un, radium, some silver, various rare earth metals, nickel, cobaltand uranium. The residue obtained by producing the so called uranium colors is the residue forming the rawmaterial in the present process. It contains the same metals except uranium.

1. 100 kg. of finely ground pitch blende residue are mixed with about 400 kg. of concentrated sulfuric acid and heated for several hours until the sulfuric acid begins to fum'e. The change of theoriginally dark brown color of the mixture to light brown or gray indicates that the compounds being): soluble in sulfuric acid, have been dissolved. The mass is then introduced into 1020 times the quantity of water, boiled, left to stand, decanted and "washed twice with water and filtered. The dry residue weighs about -50 kg. It is then heated'with 130-150 kg. of commercial caustic soda if iron crucibles until a uniform liquid molten mass or flux is obtained, which generally" occurs in one to two hours. This molten mass or flux is then boiled several times with about 1000 liters of water each time, left to stand, decanted and finally filtered. The still. moist residue is boiled with about 5 kg. of dilute sulfuric acid, preferably one part acid to ten parts of water, filtered and washed with water. The residue remaining after the last washing operation consists of the 'raw sulfate of radium. About 0.5 k of raw-sulfates are thus obtained. Said raw sulfates of radium contain 220 milligrams of raduim from 10,000 ks of raw material, and small quantities of calcium, strontiunn-lead and the like.

' 2. 100 kg. of finely ground uranium pitch residue similar to that employed in Example 1 are heated with about 250 kg. of raw commercial bisuliate of soda in clay crucibles until the sulfuric acid begins to fume: the molten mass or flux is washed several times in about 1,000 liters of Water, decanted and finally'filtered. The residue is heated with about 150 kg.- of commercial potash or sodium-potassium carbonate for about two hours, to a strong red heat, until a uniform molten mass or flux is obtained; the flux is boiled several times in about 1 000 liters of water and filtered. The residue from filtering, after being. treated with dilute suliuric acid, yields about 0.2 kg. of raw sulate.

' 3. kg. of finest ground pitch blends residue similar to that employed in Example 1, are heated for 12 hours with 200 kg. of

"caustic potash and 50 kg. of Water under agitation in a closed vessel until a pressure of 20 atm. is reached, Washed wlth Water and filtered. The residue from filtering is left to stand with 300 kg. of-concentrated I a uniform molten mass or flux is obtained.

' The flux after cooling is washed thoroughly with distilled water and filtered and the residue is dissolved in 4 kgz of hydrochloric acid free from sulfuric acid, the solution diluted with water and filtered and the filtrate is completely evaporated. residue obtained is raw chlorid of radium which can be converted in a Well known manner into pure chlorid of radium, for instance by way of fractional crystallization. The raw chlorid is radium chlorid contaminated by other-chlorids, such as the chlorids of barium, calcium, lead, etc. Itaw chlorid contains approximately 1 part of .radium chlorid and 33. parts of other "chlorids.

well known bath mixtures, such as iodin salts, iron salts, mud, and so on, in solid or liquid form, in air-tight vessels, until the highest activity is reached.

Having thus described our invention, we claim:-

1. Process of extracting radium compounds from' radium containing material, which consists in treating said material in separate operations with a strong acid reagent containing the sulfate radical, at.an elevated temperature and with an alkaline reagent, washing the residue after each operation and separating the radium salt from the resultinnq residue.

2. Process of extracting radium 'compounds from radium containing material, which consists in treating the said'material sulfuric acid and with an alkaline reagent, washing the residue after each operatlon,

which consists .in'treating the said material in separate operations w1th concentrated sulfuric acid at an elevated temperature,

The solid and separating the radium salt from the 3. Process of extracting radium com-' In the above examples, instead of caustic in separate operations with concentrated and with an alkaline reagent, washing the residue after each operation andseparating the radium salt from the resulting residue.

ing and filtering the residue, treating such residuewhile it is subjected to a suitable degree of heatwlth caustic alkali, Washing and. filtering the resulting residue, and

treating the, last said residue with dilute sulfuric. acid, substantially as described.

In testimony whereof we have signed our names to this specification in the presence 15 of two subscribing witneses.

VVit-nesses:

VICTOR TISDILI, AUGUST FUGGER. 

